Why is not Tomasini from DTO pd in USA?

[JDH]

This question references page http://imslp.org/wiki/Category:Tomasini,_Luigi
These are urtext, scholarly editions published before 1973, but not in the US (if they were published in the US, there is insufficient original content to justify copyright, in my opinion).
Since the parts are direct extractions from the DTO scores, nothing is added to make them different in status from the scores.
Why are they not, therefore, in pd in the US?

[Carolus]

If the 1973 DTO volume was published with a valid notice (and I recall that they were from the 1960s onwards), the work is under copyright in the USA for 95 years from the date of publication. While it is highly unlikely that such an edition would actually stand a court challenge due to a failure to meet the threshold of originality, the problem remains that it is legally under copyright until proven otherwise. If you happen to have the complete volume and find no notice of copyright anywhere in the volume, I can re-tag it as "C" which will free it up in the USA. The US has no special provisions in the law for urtext, which causes much grief. Also, if you happen to know of a reprint of these items by Kalmus, Masters, Dover, etc. - it's a good indication that the notice requirement was not followed (dropping the ball even for one printing - a relatively small number of copies - invalidates the claim for an item like this) and that the item is actually free in the US.